6-amino-5-acenaphthenecarboxylic acid and process of making same



Patented Jan. 1, 1929.

UNITED STATES PATENT" OFFICE.

WILHEII sonar, OF HOOHST-ON-THE-HAIN, GERMANY, ASSIGHOB 'IO GRASSELLIDYESTUTI' CORPORATION, '03 NEW YORK, N. Y., A CORPORATION OF DELAWARE.

G-AIINO-fi-ACENAPHTHBHECABIBOZYLIC ACID AND PROCESS MAKING SAME.

Io Drawing. Application filed July 5, 1927, Serial No. 208,678, andGermany mi 24, 192.6,

Inc-01! OOH Now I have found that the said acid, or salts thereof, canbe prepared by treating with a reducin agent thefi-nitro-acenaphthene-5-carboxy '0 acid obtainable by nitrating the5-acenaphthenecarboxylic acid.

The new acena hthene compound is a valuable parent p not for themanufacture of vat dyestufis.

The followin examples serve to lllustrate my invention, ut are notintended to limit it thereto, the parts being parts b welght.

1. 40 parts of G-nitro-acenapht ene-5-carboxylic acid are dissolved inan excess of ammonia and to the resulting solution there is slowly addeda solution of 280 parts of ferrous sulfate in water. During thisoperation the green color of the ferrous hydroxide changes to a browncolor. When the operation is finished, it is advantageous to heat themixture for a further short time to 70 C.80 (3., to filter it ofi warmand to precipitate the filtrate with a mineral acid, for instancehydrochloric acid. 0

The hydrochloride of the 6-am1noacenaphthene-5-carbo lic acid which hasseparated is filtered on y suction, washed until neutral and dried. Itoccurs as colorless prisms havin a melting point of about 300 C.

gentle boiling fora short time. The uncon .sumed zlnc dust is filteredoil by suction and the new compound isprecipitated from the filtrate bythe addition of a mineral acid.

.The new compound may be purified b redlssolution in water andprecipitation with a concentrated mineral acid. Its properties areidentical with those of the product obtainable according to Example 1.

3. 10 parts of '6-nitro-5-acenaphthenecarboxylic acid are introducedinto 150 arts of concentrated hydrochloric acid and ere are thengradually. added, whil e stirring, parts of stannouss chloride. 'Afterhaving stirred the mixture for 8 hours at ordinary temperature it isheated for another three hours to 70 G.80 C. The mass is then dilutedwith water, the resulting colorless roduct is filtered by suction andwashe with water. The product thus obtained is dissolved in dilutedammonia, the solution is filtered and acidified with hydrochloric acid.In this manner the hydrochloride of the 6-amino-5-acenaphthenecarboxylic' acid is separated, the properties of which areidentical with those 0 the products obtained according to the foregoingexamples. a

I claim:

general formula HaO'-OH! OOH wherein X represents-one of thesubstituents NH, and -NH .acid.

2. As new products the compounds of the general formula Inc-om 2. to asolution of 10 parts of G-nitroacenaphthene-S-carboxylit: acid in anexcess of concentrated ammonia are gradually introduced, while heatingand stirring, 20 parts ofainc dust and this mixtureisheated toaoldJI-N-ii con i 3. As a new product the hydrochloride of6-amino-acenaphthene-5-carboxylic acid of needlesjhaving a melting pointof about 10 the formula 300 (3., being soluble nearly colorless in hotwater, in concentrated sulfuric acid and in ammoma.

5 In testimony whereof, I aflix my signature.

HUI-H 00H DR. WILHELM EGKERT. vhich is diazotizab lo and forms colorlessv

